Since no one else is talking about this and I have the time to spare at the moment, I decided to go through the actual ATF document. Keep in mind, I'm not a lawyer and all the legalize is kind of hard to understand at time, but this is the current situation to my understanding.
Nothing has changed essentially. The only change is that now if you sell a completed 80% firearm (meaning it's now a full operational firearm) the FFL it has to go through has a new updated format they're required to use to stamp a serial number on it. They also formally reaffirmed their "previous decision" that "Buy, Build, Shoot" kits are "firearms". So companies like Polymer 80 that stopped selling full kits and break up everything into 3 or 4 purchases aren't affected by this at all.
If I understood it all, we're still able to buy upper and lowers, trigger packs, gun parts, etc. etc. without going through and FFL so long as it's not part of a kit. In other words, assuming I managed to actually understand it all, nothing has changed give most states already required you to serialize a home made gun before selling it, and this is yet another ineffectual attempt of the resident to get a "win" when he knows what he's doing has no teeth.
Again, not a lawyer, but this is my understanding of the final ruling. Here's the document if you guys want to read it yourselves.
My bad, had a brain fart while typing.